If you're looking to improve the appearance of your smile, tooth whitening treatments — whether done at home or in our office — are a popular option. Here are the answers to some questions that many people ask before they begin the process.

Q: Are commonly used tooth-whitening methods safe?

A: Yes — provided they are used as directed. A large body of research has shown that using the correct concentration of peroxide — the bleach that whitens teeth — for the proper amount of time is not known to cause any major health problems. However, there have been cases where poor-quality bleaching solutions and/or excessive usage have caused deterioration of tooth enamel and extreme gum sensitivity. Always follow our office's recommendation.

Q: Does this mean I have to have in-office treatments to whiten my teeth?

A: No. But you should come in for a thorough dental examination, with x-rays, before you begin whitening treatments. Why? Because if there is trouble with the underlying tooth structure, then whitening the tooth is like painting over rusty metal: It hides the symptom, but doesn't fix the problem. Abscesses and root-canal problems are just two of the underlying causes of tooth discoloration that should be treated before teeth are whitened.

Q: What are some different methods for whitening teeth, and how long do they take?

A: The fastest is in-office whitening treatments, using a strong bleaching solution and appropriate gum protection. Next comes the cost-effective method of at-home bleaching with custom-made flexible plastic trays (sometimes called nightguard vital bleaching.) If you're not in a hurry, over-the-counter (OTC) products can do the same thing — given enough time. One study comparing different whitening treatments found that a six-shade improvement in whitening was accomplished by three in-office treatments. A week was needed for custom-tray bleach applications, or 16 daily applications of OTC products, to achieve comparable results.

Q: Can any tooth be made bright white?

A: No. Every tooth has a maximum level of whiteness, beyond which it can't get any lighter. Furthermore, fillings, crowns and other dental restorations can't be lightened with bleach — another reason to talk to our office; we can help you achieve the best possible look for your particular smile.

Q: How long will my white teeth last?

A: It depends. No whitening method is permanent, but the typical result lasts for up to two years. To preserve that bright smile, you can take some positive steps: Avoid tobacco and beverages that stain, like red wine, tea and coffee; keep up with regular cleanings in our office; and, practice good oral hygiene at home. You can also have a touch-up treatment once or twice a year.